Photographing moving water is always a difficult proposition. Most of the difficulty lies in producing an image that best represents your vision, which may not necessarily accurately depict what was in front of the camera when the shutter was tripped. If the vision is clear, then reproducing it is simply a matter of making the camera record the scene in a way that will allow your initial vision to be transformed into a final image on the computer screen, or eventually a print. Moving water in a stream, cascade or waterfall, is fairly straight forward in that the speed at which the water moves is constant, and the shutter speed then translates that movement into streaks or a blur through the use of a longer shutter speed, or freezes the movement with a higher shutter speed. There is no “correct” shutter speed, because it is directly connected to the speed of the water itself as it travels through the stream bed, and how you want to portray that movement The shutter speeds have to be fine-tuned in the field after checking the screen on the back of the camera to see if the water’s movement was recorded as you intended. If not, then adjustments need to be made. This method is far better than just crossing your fingers back in the days of film. There is a bit of a trick to use when there is a breeze and any trees that may surround the brook/stream/etc. will also end up blurred if a longer shutter speed is used, and that is to blend two separate frames together later in your post processing. One frame is solely for the actual stream that utilizes a longer shutter speed to blur the water (low ISO, smaller f/stop, or an added filter such as a polarizer), and another frame of equal exposure using a faster shutter speed to stop any surrounding movements (larger f/stop, higher ISO). Of course, each frame needs to be taken on a tripod without moving it between images so they can be stacked on separate layers afterward in Photoshop.
Waves along the shores of a beach are another matter. The speed that waves wash up on the shore is constantly changing, initially going at a pretty good clip, but slowing to a stop when the surf reaches its maximum reach, and then increasing speed again as the water returns. Timing is also important in deciding when to trip the shutter. If the surf is to remain within the confines of the frame, as it is above, the shutter should ideally be tripped just as the foam attains its maximum reach and begins its return into the ocean. Trip it too soon and the movement will be “doubled” in one area and “singled” at its furthest reach, making for an uneven flow. If the surf will continue through the edge of the frame, then all that needs to be correctly measured is what shutter speed will provide the proper blur to the foam you wish. The other thing to consider when tripping the shutter is the action of the waves in the middle distance and their position within the frame. Try to trip the shutter just as the wave begins to crest since a longer exposure will blend it better and try to not have any wave that is on the edge as that may lead a viewers eye out of the frame, as they do in the photo below. Since it is probably most important to time the surf correctly, it is probably a good idea to make several attempts so that there are choices in determining which is the best from that day. Or, you can choose the best surf and the best middle ground waves to be blended together later.concept to consider
Another point about the waves as they run up on the shore, is in which direction they are flowing. Does the surf flow straight into the beach? at an angle? or does the surf flow across or parallel to the beach? Often times, two waves may flow into one another making interesting designs in the water as they meld into each other. It’s always a good idea to watch the action of the waves as you’re taking your photos to see what is going on in other areas along the beach that may prove more interesting than where you may be standing at the moment. If the beach itself is very flat, then you might get some excellent sky reflections in the sheen left after a wave retreats, and the timing for the maximum reflection before the onslaught of the next wave is important as well. For the image at the top, I waited for the wave to retreat while another surge of foam was coming in but not yet at the sheen, and was able to get a bit of both, a sunrise reflection that revealed an interesting cross-hatch pattern, and have the movement in the water as well.
One note about the post processing for these ocean sunrises that is strictly a personal preference which may not be universally accepted, is the possible presence of shells and other debris in the surf or sheen. In most instances, they are a distraction to the overall serenity of the scene or to the flow of elements, or a viewers eye within the frame. I may spend quite a bit of time removing them in Photoshop using the cloning tool on a separate layer, along with all the dust spots and any other distractions, or things that just don’t seem right. Their removal does not in any way alter the emotional connection to what occurred, but does alter the absolute recording of that instant in time. This is a choice you have to make and decide in which direction you wish to go with your work. In most instances, I opt for the cleaner look.